Description:

Title: Hyperon Production, Form Factors, and Diquarks

Speaker: Kamal Seth, Northwestern University
 

Abstract: The material Universe is made of baryons. Prior to 1947 when the first strange hadrons, the lambda and kaon were discovered, only two baryons, the proton and neutron were known. The discovery of strangeness, and the third quark, the strange quark, enriched the world of baryons from having only two members, to the world containing seven new baryons, lambda0, three sigmas(0,+,-), two cascades(0,-), and one omega(-), baryons in which one or more up/down quarks of the nucleon were replaced by the more than twenty times heavier strange quarks. Naturally, it became a major question of hadron physics as to how this new species of hyperons differed from the familiar one of nucleons. However, because hyperons were not available as targets, not much progress could be made in the study of the structure and properties of hyperons before the advent of colliders. Now, sixty years later, our group has made the world’s first large momentum transfer, and good statistics measurements of hyperon production in electron- positron annihilation. Precision measurements of the systematics of hyperon pair production cross sections and the timelike electromagnetic form factors have revealed among other properties the interesting role diquark correlations play in the QCD structure of hadrons.

Keywords: Physics, Astronomy, HEP